Self-contained high-frequency oscillator



A. SENAUKE 2,469,180

May 3, 1949.

SELF-CONTAINED HIGH-FREQUENCY OSCILLATO? 5 Sheets-Sheet 1 AEEXANDLR 5m: UKF

IN V EN TOR.

I ATTORNEY May 3, 1949; I A. SE NAUKE SELF-CONTAINED HIGH-FREQUENbY OSCILLATOR 5 Sheets-Sheet 2 Filed May 10, 1946 ALEXANDER SENAUKE IN VEN TOR.

ATTORNEY Patented May 3, 1949 SELF-CGNTAINED HIGH-FREQUENCY ()SGILLATOR Alexander Senaulie, Brooklyn, N. Y., assignor to Amperex Electronic Corp, Brooklyn, N., Y.

Application May 10, 1946, Serial No. 668,711

5 Claims. i

This invention relates to self-contained high frequency discharge apparatus for generating ultra-short waves of relatively great power.

An object of the invention is to provide a Vacuous envelope containing two electrode organizations and associated coupling elements with the required lead-in connections and constituting a self-contained ultra-high frequency oscillator.

Another object of the invention is to provide a self-contained ultra-high frequency oscillator discharge device wherein the electrode supports and the electrical connections are made at points of low radio frequency.

Still another object of the invention is to provide an ultra-high frequency oscillator tube including two like grid assemblies each consisting of a plurality of spaced apart tungsten rods imbedded in a common copper support providing a good heat conductive structure with a high allowable operating temperature.

A further object of the invention is to provide an air-cooled ultra-high frequency oscillator tube assembly including a tubular high temperature liner inside of a recessed end portion of a solid massive copper anode.

A still further object of the invention is to provide a cooled discharge tube including two spaced apart electrode assemblies each provided with a relatively massive tuned copper anode of relatively large heat radiating surface.

The capacitance between portions of ultra-high frequency devices must be relatively very small, and since capacity increases with increase in dimension of the electrodes, the electrodes of ultra-high frequency devices must be small.

In addition, the maximum spacing between the cathode and all other electrodes is limited at ultra-high frequencies by the transit time, or time of travel of electrons, because it is obvious that the operating frequency must be below the frequency at which the transit time becomes a considerable portion of the period of oscillation.

Still further, high cathode temperatures and high voltage space current produce a relatively large amount of heat and this condition tends to increase the size-limit problem of the electrodes.

Because of this space limiting requirement very close electrode spacing in ultra-short wave oscillator tubes, and the isolation to electrostatic action between electrodes must be considered.

Accordingly in the present invention means are provided for limiting the capacitance between the electrodes, for providing for a close spacing between the cathode elements and the anode elements, for conducting the heat from the said electrodes and for assuring a highly conductive emissive cathode. In addition the present invention further provides for electrode supports and heat conducting lead-in connections at points of low radio frequency. The present invention also provides means for cooling the said envelope and lead-in connections.

The invention also contemplates the use of pulsed filament voltage supply with the temperature surges on the said filaments coinciding with the anode voltage pulses when the radio fre quency energy is to be generated in pulses widely spaced.

The envelope of the device of the present invention containswithin it the electronic portions of two tubes and the balance of the necessary elements to comprise in total, a self-contained ultrahigh frequency oscillator. This self-contained feature effecting such higher efiiciencies than those that would be possible with conventional tubes and an external circuit because of the losses generally involved at the lead-in points and also because of the higher efficiencies resulting from the higher voltages at which such tube may be operated.

These new and novel features are set forth in the appended claims and one embodiment of the invention is described in the following specification and in the accompanying drawings in which an air cooled embodiment of my invention is described and claimed.

Figure 1 is a side view of an assembled selfcontained tube partly in sectional elevation showing the double electrode assembly and associated air cooled lead-in connections.

Figure 2 is a side view of the apparatus of Figure 1 showing the grid leads and the coupling leads.

Figure 3 is a sectional View taken along the line 3-3 of Figure 1.

Figure 4 is a sectional view taken along the line 5-4 of Figure 2.

The envelope of the ultra-high frequency tube shown in Figures 1 and 2, provided according to this invention, preferably comprises a glass bulb H] initially separated along the dotted line A-A of Figure 2 into an upper portion and a lower portion as hereinafter described. The top portion liA is formed with two inwardly extending cone shaped projections H and I2. This top portion is also formed with a side grid lead-in opening l3 (see Fig. 2) and two coupling lead-in openings l4 and I5 approximately opposite the said grid lead in. The bottom portion I'll-B is formed 3 with a large tapered bottom opening portion l6.

Two similar spaced apart sets of grid elements, each constructed of straight high temperature parallel tungsten rods 23 are each deeply imbedded in a common solid grid support 2| so as to be longitudinal of and symmetrically parallel about the vertical axis of the openings 22.

Two like cathode organizations each consisting of an equal number of lead-in heater current rods 24 and 2,5 are electrically connected to an equal number of straight parallel filaments 30, as shown in Figure 1, these filaments comprising a plurality of straight parallel heater wires arranged in a cylindrical plane about a common axis and attached to each other at their bottom ends for keeping the wires in proper spaced relation and for electrically connecting the said wires. Their attaching point is indicated as a common portion 32.

The said cathode heater filaments 30 and the associated lead-in rods 24 are electrically secured at the top ends to the external conductors 26.to 29 inclusive. Because of the low space impedance and high power dissipation required in this novel tube, the cathode is constructed of these closely spaced parallel filament wires to form an approximately cylindrical surface of electron emitting material.

In assembly the two said sets of rods 24 and 25 are first equally spaced around the inner surface of the said tubular glass portions H- A and l2-A, the hollow core shaped glass sealing portions 34 and 35 are then moved into the sealing positions shown in Figure 1 after which the said projecting portions II and [2 are sealed to the said lead-in rods 24 and 25 and the glass portions 34 and 35.

The two like cathode assemblies are then moved into the said upper portion Ill-A of the envelope It] so that the ends of the glass projections II and I2 are in alignment with the ends of the glass portions HA and l2A. Glass portions H and HA and i2 and l 2A are then sealed together.

The said grid assembly is now introduced into the upper envelope portion IQA through the bottom opening and lifted up so that the said cathode heaters 33 pass through the openings 22 of the common copper support 2| and the rod 20 is moved into position to receive the threaded end IQ of the lead-in rod l1 before it is sealed in the said upper portion |-A as hereinbefore described. n

The two relatively massive solid copper rod anodes 33 and 39 are rigidly supported in spaced apart parallel relation on the base 40 in turn attached to the supporting pedestal 42 as shown by Figures 1 and 2.

The said anodes 38 and 39 are each provided with circular recesses 48 in the unsupported ends into which are fitted tubular liner members M preferably made of tungsten and providing high temperature anode surfaces.

The anode assembly including the said copper portions 38 and 39, yoke 40 constitute a U-shaped tuned anode assembly having a relatively large cross section and correspondingly large heat radiating surface. This large anode cross-section provides for a large heat conducting capacity so as to keep down the temperature of the said anode surfaces of the said tungsten liner tube 4L A coupling assembly including the adjustable U-shaped coupling portion 41 threaded at both ends is supported in the threaded recesses of the sealed-in ooupling-lead-in rodsAB- -A and 46- -3,

The coupling portion 41 is adjustably positioned by the knurled nuts 44A and 44-3 before the sealing-in action between the said envelope portion IilB and the said rods 46A and 43-13. The said rods 46A and it-B are provided at enlarged outside portions with the cooling fins 45-A and 55-43.

The anode assembly pedestal 42 is sealed-in at the said lower portion Ill-B so as to project downwardly from the said tube as shown by Figures 1 and 2 and thereby support an air cooling assembly.

The bottom edge of the envelope portion |0A and the top edge of the portion |0B are thence placed in contact and sealed together to form the vacuous envelope Ill.

The said air cooling assembly includes sheet metal means 49 for forming the walls of a plurality of vertical air ducts 48 symmetrically positioned about the axis of the extending portion said pedestal 42 so as to form in efiect an annular honey-comb structure. The inner edges of the radially extending sheet walls are physically and thermo-conductively attached to the pedestal 42 by soldering. A metal band 49-is securely attached to the said air-cooling means by the riveted portion 53 so as to support the handle 52.

A win nut 5! is attached to the band 49-A so as to connect the said anode assembly to an external circuit.

Therefore, while I have shown and described and have pointed out in the annexed claims, certain novel features of my invention, it will be understood that various omissions, substitutions and changes in the form and details of the device illustrated or in its operation may be made by those skilled in the art without departing from the spirit of the invention. For example, the liner members 4i may be omitted. I

What I claim is:

l. A high frequency oscillator tube adapted to generate electrical oscillations at a predetermined operating frequency comprising, an evacuatecl envelope having a portion of insulating material, a U-shaped radiofrequency line of high thermal and electricalconductivity within said envelope and having anode end portions, said line having an electrical length between said end portions tuned substantially to an odd multiple half wave length at said operating frequency, a thermal and electrical conductor connected to said line at a point of substantially zero radio frequency potential intermediate said end portions and extending through said envelope portion in hermetically sealed relationship therewith, heat dissipating means in good ther mal contact with said conductor externally of said envelope, and means coupled to said conductor to connect a direct potential to said con- I ductor externally of said envelope.

2. A high frequency oscillator tube adapted to generate electrical oscillations at a predetermined operating frequency, comprising an evacuated envelope having a portion of insulating material, two cathode-grid assemblies in said envelope, an electrically and thermally conductive line'having two recessed anode end portions and having an electrical length tuned substantially to an odd multiple half wave length at said operating frequency, each of said assemblies being positioned respectively within one of said recesses, and thermally and electrically conductive means connected to said line at a point of substantially zero radio frequency potential at said operating frequency intermediate said end portions and eX- tending through said envelope portion in hermetically sealed relationship therewith.

3. A high frequency oscillator tube adapted to generate electrical oscillations at a predetermined frequency, comprising, an evacuated envelope having a portion of insulating material, a thermal and electrical U-shaped conductor member having substantially cylindrical legs having anode end portions having substantially cylindrical recesses substantially coaxial with said legs, said recessed anode end portions being adapted to surround an electrode assembly in said recesses, said conductor member having an electrical length between said anode end portions tuned substantially to an odd multiple half wave length at said operating frequency, and a second thermal and electrical conductor member electrically and thermally connected to said first conductor substantially midway between said anode end portions and extending through said envelope portion in hermetically sealed relationship therewith.

4. A high frequency oscillator tube adapted to generate electrical oscillations at a predetermined operating frequency, comprising an evacuated envelope having two portions of insulating material, two sets of elements in said envelope each comprising a cathode, a grid, and an anode, a line of high thermal and electrical conductivity electrically tuned substantially to an odd multiple half wave length at said operating frequency and having end portions each in good electrical and thermal contact with one only of said anodes, a first thermal and electrical conductor in good thermal and electrical contact with said line at a point of substantially zero radio frequency potential intermediate said line end portions and extending through one said envelope portion in hermetically sealed relationship therewith, a thermally and electrically conductive grid strap within said envelope having end portions each in good electrical and thermal contact with one only of said grids, said grid strap having an electrical length to feed signals at said operating frequency from one to the other of said strap end portions substantially in phase opposition, a thermally and electrically conductive member thermally and electrically connected to said strap at a point of substantially zero radio frequency potential intermediate said strap end portions and extending through the other said envelope portion in hermetically sealed relationship therewith.

5. A high frequency oscillator tube adapted to generate electrical oscillations at a predetermined operating frequency, comprising an evacuated envelope having two portions of insulating material, two sets of elements in said envelope each comprising a cathode, a grid, and an anode, a line of high thermal and electrical conductivity and electrically tuned substantially to an Odd multiple half wave length at said operating frequency and having end portions each in good electrical and thermal contact with one only of said anodes, a thermal and electrical conductor in good thermal and electrical contact with said line at a point of substantially zero radio frequency potential intermediate said end portions and extending through one of said envelope portions in hermetically sealed relationship therewith, a thermally and electrically conductive grid strap within said envelope having end portions in good electrical and thermal contact with one only of said grids, said grid strap having an electrical length to feed signals at said operating frequency from one to the other of said strap end portions substantially in phase opposition, a thermally and electrically conductive member thermally and electrically connected to said strap at a point of substantially zero radio frequency potential intermediate said strap end portions and extending through the other of said envelope portions in hermetically sealed relationship therewith, a first heat dissipating means connected to said first conductor externally of said envelope, means coupled to said first conductor to connect a direct potential to said first conductor externally of said envelope, second heat dissipating means connected to said second conductor externally of said envelope, and means coupled to said second conductor to connect a direct potential to said second conductor externally of said envelope.

ALEXANDER SENAUKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,721,148 Franklin July 16, 1929 1,853,632 Mouromtseif Apr. 12, 1932 1,981,058 Marconi et al Nov. 20, 1934 1,991,606 Eitel Feb. 19, 1935 2,013,419 Moran Sept, 3, 1935 2,189,501 Helbig Feb. 6, 1940 2,250,322 Atlee July 22, 1941 2,281,041 Labin Apr. 28, 1942 2,289,984 Mouromtseff July 14, 1942 2,324,766 Chevigny July 20, 1943 2,407,974 Clifford Sept. 24, 1946 

